This invention relates to an automatic guidance system for vehicles, and more particularly to an automatic guidance system for vehicles to be used, for example, in the automatic guidance of vehicles carrying various articles, wheeled beds and chairs carrying invalids and vehicles loaded with monitor systems for detection of abnormal phenomena within an atomic furnace.
For automatic guidance of vehicles, there has already been suggested a method for application to a system involving a network of roads, a fleet of vehicles, guide cables each adapted to generate an electromagnetic field of low frequency and buried one each under the surface of roads along the routes in the network of roads and laterally opposed pairs of pickup coils disposed one each on the vehicles and adapted to detect the aforementioned electromagnetic fields, which method comprises causing a given vehicle to travel along a selected route by causing the opposed pair of pickup coils on the vehicle to detect the electromagnetic field being generated by the guide cable buried under the surface of the road on which the vehicle is in motion, comparing the electric potentials induced consequently in the opposed pair of pickup coils, and allowing the vehicle to be accurately steered along the route by having the operation of a steering motor controlled in such a way as to reduce to zero the difference between the two potentials under comparison. There has also been proposed a system similar to that described above except that metallic tapes are attached to the surface of roads to take the place of buried guide cables and a plurality of photo-sensors disposed on each vehicle in one straight line perpendicular to the direction of the vehicle's travel take the place of the pair of pickup coils. In this system, a vehicle is made to travel along a selected route by causing the array of photo-sensors on the vehicle to detect the electric field being generated by the metallic tape on the road surface and allowing the vehicle to be accurately steered along the route by having the operation of the steering motor thereof controlled in such a way as to eliminate the positional deviation of the vehicle determined in consequence of the aforementioned detection of the electric field by the photo-sensors.
These methods require installation of guide cables or metallic tapes in continuous lines and the installation of such cables or tapes is expensive and time consuming. Once such cables or tapes have been laid, route changes cannot easily be made.
An object of the present invention is to provide an automatic guidance system for vehicles, which permits the travel routes to be easily established and altered.
Another object of this invention is to provide an automatic guidance system for vehicles, which enables vehicles to be accurately guided to their destinations.
A further object of this invention is to provide an automatic guidance system for vehicles, which enables vehicles to be guided faithfully along their respectively selected routes.
Yet another object of the present invention is to provide an automatic guidance system for vehicles, which enjoys ease of operation and provides safe travel of vehicles.